Centrifugal conveyer-fan.



W. S. OSBORNE. CENTRIFUGAL CONVEYER FAN. APPLICATION FILED APR. a. 1916.

Patented July 10, 1917.

Vii'lliamofl U EOMW surfaces of the blades of the fan Wheel andceedingly short life;

WILLIAM S. OSBORNE, 0F CANTON, OHIO, ASSIGNOR 0F ONE-HALF TO CLARENCEIN.

MACK, 0F CANTON, OHIO.

CENTRIFUGAL CONVEYER-FAN.

Specification of Letters Patent.

Patented July Ml, limit.

To all whom it may concern.

Be it known that I, WILLIAM S. OSBORNE, a citizen of the United States,residing at Canton, in the county of Stark and State of Ohio, haveinvented certain new and useful Improvements in CentrifugalConveyer-Fans, of which the following is a specification.

The invention relates to improvements in centrifugal conveyer fans ofthe type employed in pneumatic systems for conveying materials from onepoint to another, and more particularly to fans for conveying abrasivematerials, such as sand, coal, ashes and the like.

Fans which are employed for conveying abrasive materials are or cutthrough in a' very short space of time, by reason of the grinding andabrading action of the material, and the life of the fan in many casesdoes not exceed a week or ten days. It is thus evident that the use offans as ordinarily constructed, for this purpose, although operating toefiiciently perform their, function for a time, is almost prohibitive onaccount of their exand the object of the present invention is to providemeans for forming air cushions on the surfaces exposed to the impact ofmaterial passing through the fan for protecting the fan from theabrading action of the material which is being conveyed, and to prolongthe life of the fan indefinitely, such means being simple inconstruction and not materially increasing the cost or impairing theefliciency of the fan.

The object of the invention thus set forth in general terms, is attainedby providing a plurality of transverse ribs on the forward frequentlyworn out on the inner surface of the peripheral wall of the fan casing,which ribs are spaced a short distance apart and form pockets. In theoperation become filled with air which is compressed and forms an airlining or cushion on each of the blades and on' the peripheral wall ofof the fan these pockets,

the casing, for receiving the impact of the material passingtherethrough.

preferred embodiment of my invention is illustrated in the accompanyingdrawings forming part hereof, in which- Figure 1 is an end elevationpartly in section of the conveyer fan;

Fig. 2, a sectional view of the case. on line 2-2, Fig. 1, showing thefan wheel therein;

Fig. 3, a fragmentary perspective view of one of the rib plates orsections for the casing; and

Fig. 4, an enlarged sectional view showing the manner of securing theribs to the fan blades.

Similar numerals refer to similar parts throughout the drawings.

In the embodiment illustrated, the fan comprises a, caslng 1, mountedupon a base 2, and a fan wheel 3 mounted to rotate within the casing onthe inner end of a drive shaft 4 extending through an opening 5 in therear side wall of the case, and mounted in bearings 6 supported on eachside of a drive pulley 7 thereon, by means of a standard 8 at the rearside of the casing.

The casing 1 is preferably of the snail type having a substantiallyaxial eye or inlet opening 9 in its front side wall 10, and a tangentialdischarge nozzle ing 11 in its peripheral wall 12, at the lower end ofthe casing; and the fan wheel 3 consists of a plurality of vanes orblades 13 secured by means of rivets 14 transversely of the case on aplurality of T-arms 15 Whlch extend radially from a hub 16 keyed on theshaft 4, said blades being located in planes substantially parallel withthe axis of rotation of the fan wheel.

For the purpose of protecting the parts of the fan which are exposed tothe impact of the material which is drawn therethrough, the innersurface of the peripheral Wall 12 of the fan casing is provided with aplurality of transverse and preferably rectangular ribs 17 spaced ashort distance apart to form pockets 17 8 therebetween, said or outletopenthe peripheral 4 of the air currents as ribs being equalinlength tothe interior width of the casing and being located substantiallyparallel with the axis of ro tation of the fan wheel; and the forwardfaceof each of the fan blades 13 is provided with a plurality of ribs 18extending transversely across the blades and also, spaced apart to formpockets 18 therebetween, the length of said ribs and pockets beingsubstantially parallel with the axis of rotation.

For the purpose of construction, and for convenience in assembling, theribs 17 for the peripheral wall are preferably formed or castintegrallywith a plurality of rela- ;-tively short plates or sections 19which plates are curved to conform to the shape of the peripheral wall12 and are secured thereto in a continuous series as by means of bolts20 entered through apertures 21, provided at the opposite ends of thesections for that purpose; and the ribs 18 are preferably secured to thefan blades 13 y means of tapered rivets 22 entered throu hcorrespondingly shaped apertures 23 in the ribs.

In operation, as the fan wheel is rotated by the drive pulley 7 theinner surface of wall is impinged by the air and a quantity thereof isforced into the pockets 17 and is retained and compressed therein to asubstantial degree by the action they are thrown radially outwardthereagamst; and likewise the fans of this type,

1 overcome by the as the forward surfaces of the blades of the fan wheelimpinge the air, the pockets 18 alsobecome filled with air, which iscaught and compressed therein as its inertia is action of the fan wheel.It is thus evident that the air which is retained by the pockets on theinner surface of the peripheral wall, forms a continuous layer or liningof compressed air on the entire inner surface of the peripheral wall,and that the airwhich is retained by the pockets on the forward face ofthe fan blades, forms a sim'lar linin thereon; so that the impingingaction 0 the material drawn into the fan is receivedand cushioned by theprotecting air linings in the casing and on the blades, largely limitingor preventing the grinding and wearing of the parts, and prolonging thelife of the fan. In order that the power required to drive the fan shallnot be increased by the presence of the transverse ribs on theperipheral wall, the fan casing is made relatively shghtly larger indiameter than is'usual in so that suflicient clearance is providedaround the periphery of the wheel for the most eflicient operation ofthe fan; and on account of a tendency of the ribs 18 on the face of thefan blades to form eddy currents, when they are all of the same size,said ribs are preferably gradually increased inthickness toward the tipsof the blades so that their forward faces will lie in a radial plane andthe outer walls of the pockets formed between them will serve toeffectively prevent the air from whirling outwardly from one pocket toanother.

I claim 1. A fan includin a casing having an inlet opening, an outet'opening, and a peripheral wall, a wheel mounted to rotate in thecasing having a plurality of blades, there being a plurality oftransverse ribs spaced apart on the inner surface of the peripheral walland a plurality of trans verse ribs spaced apart on the forward face ofthe fanblades.

2. A fan includin a casing having an inlet opening, an out et openingand a peripheral wall, a wheel mounted to rotate in the casing, and .aplurality of transverse ribs spaced apart on the inner surface of theperipheral wall.

3. A fan including a casing having an inlet opening and an outletopening, a wheel mounted to rotate in the casing having a plurality ofradial blades, and a plura ity of'transverse ribs spaced apart on theforward face of the fan blades, the planes of the blades and the lengthof the ribs being substantially parallel with the axis of rotation.

4. A fan including a casing having an inlet opening and an outletopening, a wheel mounted to rotate in the casing having a plurality oftransverse blades, and a plurality of transverse ribs spaced apart onthe forward face of each of the fan blades and having their forwardedges lying in the same radial plane.

5. A fan includin a casing having an inlet opening, an out et openingand a pcripheral wall, a wheel mounted to rotate in the casing, and aplurality of plate sections secured in a continuous series on the innersurface of the peripheral wall, said sections having a plurality of airpockets formed therein.

6. A fan includin inlet opening, an out et opening and a peripheralwall, and a wheel mounted to rotate within the casing and having aplurality of blades, there being a plurality of air pockets on the innersurface of the peripheral wall and on the forward faces of the fanblades.

7. A fan includin a casing having an inlet opening, an ou et opening anda pcripheral wall, and a fan wheel mounted to rotate within the casing,there being a plurality of air pockets on the inner surface of theperipheral wall.

8. A fan including a casing having an a casing having an weenie inletopening and an outlet opening, and a Wheel mounted to rotate Within thecasing and having a plurality of radial blades, there being a pluralityof air pockets on the forward surfaces of the blades, the planes of theblades being substantially parallel with the axis of rotation.

9. A centrifugal conveyer fan including a wheel having blades and acasing having a wall, said blades and Wall having ribs forming airretaining pockets on the sur- :laccs which impinge and are impinged bythe air.

10. A rentrifugal conveyer fan including a wheel having blades Whosefaces are substantially parallel to the axis of rotation of the wheel.said blades having ribs forming air retaining pockets on the surfacesWhich impinge the air.

I]. A centrifugal conveyer fan including a casing having a Wall providedwith ribs forming air retaining pockets on the surface which is impingedby the air.

l2. A centrifugal conveyer fan including a: Will a Wheel having bladeswall, said blades and wall being provided with a plurality of airretaining pockets in the surfaces which impinge and are impinged by theair.

13. centrifugal conveyer awheel having blades Whose stantially parallelto the anti the wheel, each of said blade with a plurality of air retathe surfaces which iin ii. A centrifugal eon "in including a casinghaving a Wall provided With a plurality of air retaining pockets in thesurface which is impinged by the air.

. 15. A centrifugal conveyer fan having in combination, a casing havinga, vi -all and an impeller having blades said Wall and blades havingsurfaces exposed to the impact of material passing through the fan, andmeans for forming a protecti e air cushion on one of said surfaces.

fan including :laces are subs of rotation of heing provided 11g; pocketsin i/VlLLlAh'i' S. afltiritllltl lllfl.

and a casing having a f

